LASER WAVELENGTH CONTROLLER, GAS CONCENTRATION MEASURING DEVICE, LASER WAVELENGTH CONTROL METHOD, AND GAS CONCENTRATION MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To accurately match the absorption wavelength of gas with the emission wavelength of semiconductor laser without depending on measuring environment.;SOLUTION: Laser light with modulated frequency is branched to a gas cell 44, and after it passes through the gas cell 44, it enters an optical detection part 45 on the sending side. An amplification ratio between the fundamental wave component and the doubled wave component of the laser light passing the gas cell 44 is calculated by a sending part substrate 54, and the temperature of the semiconductor laser 41 is so set that the wavelength of the laser light emitted from the semiconductor laser 41 may be matched with the absorption peak wavelength of the gas cell 44. Furthermore, wavelength modulation is conducted referring to a wavelength shifted from the absorption peak wavelength as reference, and the driving current of the semiconductor laser 41 is controlled at the same time. Thus, the absorption wavelength of the gas cell 44 is matched with the emission wavelength of the semiconductor laser 41.;COPYRIGHT: (C)2008,JPO&INPIT